The five surviving members of INXS have traced the mental decline of Michael Hutchence to a vicious attack on the frontman five years before his lonely death in a Sydney hotel.

Hutchence was on a night out in Denmark in August 1992 with then girlfriend Helena Christensen when he was punched by a taxi driver. Hutchence fell to the pavement, fracturing his skull and losing his sense of taste and smell.

''When Michael hit his head, he came back a different person and I'm sure doctors were prescribing all sorts of weird and wonderful concoctions,'' he told the program.

''He was a dick and it wasn't him, that's the thing. It wasn't the Michael we knew and that's what was so surprising. He couldn't smell, he couldn't taste, he was drinking wine by the bottle 'cause it was just like nothing to him.''

Founding member Tim Farriss said Hutchence was more aggressive after ''that knock on the head''.

''He was very passionate about the sense of smell and taste, you know, food and wine,'' he said.

The band members of INXS have been criticised by Hutchence's half-sister, Tina, for their participation in the biopic INXS: Never Tear Us Apart, which she says trashed the reputation of her family and turned Hutchence's life into a soap opera.